Various types of conversion machines heretofore have been used to convert sheet stock material composed of one or more plies of sheet material into a dunnage product. Some machines function solely to produce a void fill dunnage product, used primarily to fill voids in a packaging container to prevent the contents thereof from shifting during shipment. One objective in the design of these machines is to produce the void fill dunnage product very rapidly. Accordingly, these machines are designed to operate at relatively high speeds.
Other machines function to produce a dunnage product having cushioning characteristics which enable the dunnage product to, for example, cushion or secure an article in a container from damage which may not otherwise be obtainable from a void fill dunnage product. Such machines usually produce the dunnage product at a relatively slower rate than void fill producing conversion machines to enable deforming or shaping of the sheet material to, for example, impart adequate loft into the resulting dunnage product. Thus, with these machines often speed is sacrificed to achieve a dunnage product characterized by substantial cushioning properties. The trade off is a slower production rate of the cushioning dunnage product as compared to the void fill dunnage product.
However, attempts to achieve a dunnage conversion machine capable of producing a void fill product at relatively higher speeds while still maintaining an adequate void fill and/or cushioning capability have not been without problems. Thus, some conversion machines may fail to impart sufficient loft, or an adequate low density, to the sheet material to be converted, resulting in a dunnage product having an undesirably flat, essentially two dimensional, configuration rather than a more desirable three dimensional void fill configuration. In this instance, manual labor is often used to further convert, e.g., crumple, the dunnage product so that it has more desirable void fill capability. Also, the inventors of the present invention have observed that in some dunnage conversion machines the feeding device may engage the sheet stock material at a concentrated portion thereof and/or too abruptly causing sudden increases in the tension of the sheet material which may tear and/or jam the machine, or otherwise deleteriously affect the cushioning characteristics of the dunnage product, or its ability to adequately protect against damage or breakage of the item to be protected.
Thus, it would be desirable to provide a more effective and efficient conversion machine and method suitable for producing a void fill material having adequate void fill capabilities as well as cushioning characteristics (if desired), for example, one which is lightweight with a low density, yet stable, making it suitable for filling the void space around an article to be packaged and for at least minimally protectively cushioning the article from damage during storage or shipment. More particularly, it would be desirable to provide improved speeds at which the dunnage conversion machine operates and consequently its corresponding output rate, while keeping with the objective of providing a void fill product having at least minimal cushioning characteristics.